Methods and devices for protecting a passageway in a body when advancing devices through the passageway

ABSTRACT

A liner is advanced through a narrowed region in a vessel such as the internal carotid artery. The liner is advanced through the narrowed region in a collapsed position. A stent is then advanced through the liner and expanded to open the narrowed region. The liner may also have an anchor which expands an end of the liner before the stent is introduced.

BACKGROUND OF THE INVENTION

[0001] The present invention is directed to methods and devices forprotecting a passageway in a body when advancing devices through thepassageway. A specific application of the present invention is fortreatment of blood vessels although the invention may be used in anypart of the body. For example, the present invention is used to protectblood vessels during intravascular procedures for treating aneurysms,arteriovenous malformations, and atherosclerotic disease of vessels. Aparticular application of the present invention is for atheroscleroticdisease of the carotid arteries or saphenous vein grafts. Carotid arteryatherosclerotic occlusive disease contributes to hundreds of thousandsof strokes annually in the United States. Atherosclerotic disease of theinternal carotid artery is particularly problematic since plaquedislodged from the internal carotid artery leads directly to thecerebral vasculature.

[0002] A conventional method of treating carotid artery occlusivedisease is by surgical removal of the plaque (carotid endarterectomy).The carotid artery is opened surgically, the plaque is removed and thecarotid artery is then closed. Carotid endarterectomies havedemonstrated significant clinical benefit over conservative treatmentwith medication by reducing strokes over the next five years. Althoughcarotid endarteretomy reduces strokes over a period of time after theprocedure, the procedure still has a 6% risk of death or stroke.

[0003] Another method of treating carotid artery disease is to useinterventional devices such as stents. A problem with treating carotidartery occlusive disease with stents is that the user is wary ofdislodging plaque when advancing the stent through the carotid artery.Any plaque which breaks free during introduction of the stent travelsdirectly to the patient's brain and can cause a stroke or death.

[0004] Yet another method of treating carotid artery occlusive diseaseis to introduce a filter through the carotid artery to trap embolireleased during subsequent deployment of a stent or angioplasty balloon.This method suffers the same drawback in that advancement of the filteritself may dislodge plaque. Moreover, exchange of various therapeuticcatheters over the filter element result in undesirable movement of thefilter with attendant risk of losing filtered emboli or damaging thevessel wall with the filter.

[0005] The present invention is directed to improved methods ofprotecting a body passageway when advancing devices through the bodypassageway. The present invention is also directed to improved methodsof treating atherosclerotic vessels and, in particular, occlusivedisease of the internal carotid artery.

SUMMARY OF THE INVENTION

[0006] In accordance with the objects of the invention, a liner isprovided to protect a body passageway during introduction of otherdevices into the passageway. In a specific application, the methods anddevices of the present invention are used to protect blood vessels, suchas the internal carotid artery, during intravascular procedures. It isunderstood that use of the present invention for protection of bloodvessels is discussed as an example of how the present invention may beused, however, the invention may be used in any other part of the bodywithout departing from the scope of the invention. The liner iscollapsed for introduction into the patient and advanced to a narrowedregion of a blood vessel. The liner is passed through a region of theblood vessel in the collapsed condition and an intravascular device,such as a stent or filter, is then introduced into the liner. The linermay be used to protect vessels from any type of problem includingatherosclerotic disease, perforation, aneurysm or AVM.

[0007] The liner protects the vessel as the intravascular device ispassed through the region to prevent the device from dislodging plaque.When the device is a stent, the stent is preferably expanded within theliner to trap the liner between the stent and the vessel. The liner maybe expanded by the stent or may be partially or fully expanded beforeintroduction of the stent. The devices and methods of the presentinvention are particularly useful for treating occlusive disease of theinternal carotid artery. The liner may be any suitable material andsuitable materials include expanded PTFE, woven dacron, nylon, lowdurometer silicone, or thin-walled polyethylene.

[0008] The liner is preferably mounted to a delivery catheter and isadvanced over a guidewire. The liner may have an anchor at a proximalend which is used to open the proximal end of the liner. The anchor maybe self-expanding or balloon expandable. Once the proximal end of theliner is opened, the liner can be designed so that blood pressure opensthe liner. Alternatively, the liner may open automatically or may beopened with a separate device, the delivery catheter or the stentitself. When treating occlusive disease of the internal carotid artery,the anchor may be positioned completely in the internal carotid arteryor may extend from the common carotid artery across the bifurcation ofthe internal and external carotid arteries and into the internal commoncarotid. The anchor preferably has an open structure which permits bloodflow into the external carotid artery.

[0009] The liner may be an elastic liner or may be folded into acollapsed position. The liner may be collapsed in any suitable mannerand preferably has a number of folded sections which are wrapped aroundone another. The folded sections are preferably adhered to one anotherto hold the liner in the collapsed position. The folded sections may beadhered together by application of heat or with an adhesive or coating.The distal end of the liner may be coated to form a curved surface whichcovers the ends of the folded sections. Alternatively, the ends of theliner may be scalloped or contoured so that when folded the edge tapersdown more cleanly.

[0010] The liner may also be designed to evert when expanding. Theeverting liner reduces sliding between the liner and vessel so thatplaque is not dislodged when introducing the liner. An end of theeverting liner may be releasably attached to the delivery catheter.

[0011] The proximal end of the liner may also be opened with anexpandable device, such as a balloon, on the delivery catheter ratherthan with an anchor attached to the liner. Once the proximal end isopen, the stent or other device is advanced through the liner.

[0012] In yet another aspect of the invention, the catheter holds theproximal end partially open. The stent or other device is then advancedthrough the open proximal end. The liner can be released when using astent or may be removed after use.

[0013] These and other features and advantages of the invention willbecome evident from the following description of the preferredembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 shows a system for advancing devices through a narrowedregion of a blood vessel such as the internal carotid artery.

[0015]FIG. 2 shows a liner advanced through the narrowed region in acollapsed position.

[0016]FIG. 3 shows the liner detached from the delivery catheter andexpanded.

[0017]FIG. 4 shows only the proximal end of the liner expanded with ananchor.

[0018]FIG. 5 shows the liner having openings or perforations.

[0019]FIG. 6A shows the liner having a woven or braided configuration.

[0020]FIG. 6B shows the liner having a radiopaque maker and a scallopeddistal end.

[0021]FIG. 7 shows the liner folded into six folded sections.

[0022]FIG. 8 shows the folded sections wrapped around one another.

[0023]FIG. 9 shows an end view of the liner of FIG. 7.

[0024]FIG. 10 shows an end view of the liner of FIG. 8 with the linerwrapped around a guidewire.

[0025]FIG. 11 shows the liner having four folded sections.

[0026]FIG. 12 shows the liner of FIG. 11 with the folds wrapped aroundone another.

[0027]FIG. 13 shows a coating over a distal end of the liner.

[0028]FIG. 14 shows the coating extending over the length of the liner.

[0029]FIG. 15 is a cross-sectional view of the liner and coating withfour folded sections.

[0030]FIG. 16 is a cross-sectional view of the liner and coating withsix folded sections.

[0031]FIG. 17 shows a sheath covering the liner in the collapsedcondition.

[0032]FIG. 18 shows a filament tearing a distal end of the sheath.

[0033]FIG. 19 shows the liner attached to the anchor.

[0034]FIG. 20 shows the liner attached to a tapered anchor.

[0035]FIG. 21 shows an anchor contained entirely within the internalcarotid artery.

[0036]FIG. 22 shows the balloon expanding the anchor and blocking bloodflow into the internal carotid artery.

[0037]FIG. 23 shows the liner and anchor of FIG. 22 deployed.

[0038]FIG. 24 shows a balloon-expandable stent introduced into theliner.

[0039]FIG. 25 shows the stent expanded.

[0040]FIG. 26A shows an elongate element which opens the distal end ofthe liner.

[0041]FIG. 26B shows the elongate element contained within a tube duringdelivery of the liner.

[0042]FIG. 26C shows the elongate element of FIG. 26B advanced into apocket of the liner to open the proximal end of the liner.

[0043]FIG. 26D shows the stent introduced into the liner of FIG. 26C.

[0044]FIG. 27 shows the delivery catheter for the anchor used to delivera stent into the liner.

[0045]FIG. 28 shows the distal end of the stent of FIG. 27 expanded totrap plaque behind the liner.

[0046]FIG. 29 shows the delivery catheter for the anchor used to delivera distal anchor.

[0047]FIG. 30 show the delivery catheter in position for delivering thedistal anchor.

[0048]FIG. 31 shows the distal anchor deployed so that the proximal anddistal ends of the liner are expanded.

[0049]FIG. 32 shows another stent delivered between the proximal anddistal anchors.

[0050]FIG. 33 shows the stent of FIG. 32 expanded.

[0051]FIG. 34 shows a delivery catheter having an expandable section foropening the proximal end of the liner.

[0052]FIG. 35 shows the proximal end of the liner opened with theexpandable section.

[0053]FIG. 36 shows the stent advanced through the liner.

[0054]FIG. 37 shows the stent partially expanded.

[0055]FIG. 38 shows the stent expanded into contact with the vessel walland the liner released from the delivery catheter.

[0056]FIG. 39 shows the stent fully expanded.

[0057]FIG. 40 show a filter passed through the liner.

[0058]FIG. 41 shows the liner everting when deployed.

[0059]FIG. 42 shows the liner partially everted.

[0060]FIG. 43 shows the liner almost completely everted and the distalend released.

[0061]FIG. 44 shows the liner released from the delivery catheter.

[0062]FIG. 45 shows another delivery catheter which holds the proximalend of the liner open.

[0063]FIG. 46 shows the stent advanced through the liner of FIG. 45.

[0064]FIG. 47 shows another delivery catheter for the liner.

[0065]FIG. 48 shows still another delivery catheter for the liner.

[0066]FIG. 49 shows yet another delivery catheter for the liner.

[0067]FIG. 50 shows a distal end of the liner trapped in a fold.

[0068]FIG. 51 shows a kit having devices and instructions for use inaccordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] A system 2 for protecting vessels during intravascular proceduresis shown in FIGS. 1-4. Although the present invention is described inrelation to treatment of atherosclerotic disease of the internal carotidartery and the particular problems encountered when working in thecarotid arteries, the liner may be used in other vessels such assaphenous vein grafts of coronary bypass procedures, iliac and coronaryarteries. A guide catheter 4 is introduced through the femoral arteryand advanced to the common carotid artery in the conventional manner.The guide catheter 4 has a hemostasis valve 6 which receives a linerdelivery catheter 8. The guide catheter 4 may be omitted withoutdeparting from the scope of the invention.

[0070] A liner 10 is used to protect the body passageway when passingother devices through the body passageway. For example, the liner 10 maybe used to protect the carotid artery to prevent plaque from beingdislodged when passing other devices through the carotid artery. Aproximal end 11 of the liner 10 may be attached to an anchor 12 whichexpands and opens the liner 10 and holds the liner 10 against the vesselwall to reduce or eliminate flow around the liner. The liner ispreferably nonmetallic and is relatively flexible to conform to the bodypassageway. The anchor 12, as will be discussed below, is mounted to oneend of the liner 10 while the other end of the liner 10 is preferablyfree.

[0071] The liner 10 is advanced through the vessel in the collapsedcondition of FIG. 2 so that the liner 10 can be advanced through smallor highly stenosed vessels. After the liner 10 is in position, otherdevices, such as a stent 26 (FIG. 25) or filter (FIG. 40), may be passedthrough the liner 10 so that the liner 10 prevents contact between thedevice and the vessel wall. The liner 10 may also be used to protect thevessel when advancing other devices such as angioplasty balloons, drugdelivery catheters, laser catheters or ultrasound catheters. FIG. 3shows both ends of the liner 10 opened to trap plaque behind the liner10 so that loose plaque cannot flow downstream. The liner 10 ispreferably delivered over a conventional guidewire 15 which has a0.010-0.018 inch diameter but may be of any other suitable sizedepending upon the vascular site.

[0072] The liner 10 is preferably made of expanded PTFE having athickness of 0.006 to 0.002 inch, more preferably 0.001 to 0.002 inchand most preferably about 0.001 +/−0.0005 inch although any othersuitable material may be used. For example, the liner 10 may have awoven construction such as silk or polyester as shown in FIG. 5. Theliner 10 may also have small openings 25 or perforations which actsimilar to a filter in that they permit blood to flow through butprevent large emboli from escaping (FIG. 6A). The openings 25 also maypromote tissue growth. Referring to FIG. 6B, the liner 10 may also havea scalloped distal end 7 to form a smoother transition at the distal endwhen collapsed. The liner 10 may also have a radiopaque marker 9, suchas a 0.002 inch by 0.008 inch platinum ribbon, embedded, sewn, or foldedinto the liner 10. The liner 10 may have the markers 9 extendinglongitudinally (FIG. 6B) or circumferentially. When the markers 9 extendlongitudinally, three markers 9 are preferably provided 120 degreesapart.

[0073] The liner 10 may also be elastic so that the liner 10 remainssubstantially cylindrical and without folds in the collapsed andexpanded positions. When using an elastic liner 10, the liner 10 ispreferably a tube of low durometer silicone, latex or natural rubber,thermoplastic elastomers such as Kraton or hydrogenated thermoplasticisoprenes having a thickness of 0.001 to 0.0005 inch. Alternatively, theliner 10 could be made of an inelastic but plastically deformablematerial. Initially the liner 10 would be sized to allow easy passage ofthe devices such as the balloons, stents and filters described herein.The liner 10 is then plastically deformed by the devices which passtherethrough. For example, a pre-dilatation balloon may be introduced todilate the liner 10. The stent 27 can then be advanced into the dilatedliner 10 and expanded to open the narrowed vessel. Expansion of thestent continues plastic deformation of the liner 10 to a final size. Anyof the liners 10 described herein may be substituted for any of theother liners 10 without departing from the scope of the invention.

[0074] FIGS. 7-12 show a preferred method of collapsing the liner 10.The liner 10 is folded longitudinally along creases 13 to create atleast 2 and preferably 4-6 folded sections 14. Four folded sections 14are shown in FIGS. 11 and six folded sections 14 are shown in FIG. 7 and9. The folds 14 are then wrapped as shown in FIGS. 8, 10 and 12. Theliner 10 may, of course, be wrapped in any other manner. For example,the liner 10 may be spiral wrapped or randomly compressed and set withhigh pressure and/or heat. The folded sections 14 may be adhered to oneanother by application of heat which holds the folded sections 14together without melting and fusing the sections 14 together. Anothermethod of holding the liner 10 in the collapsed position is to apply anadhesive 16 such as medical grade glue, cyanoacrylates, epoxies,ultraviolet activated adhesives, low molecular weight polyvinyl alcoholpolymer, gelatin and sucrose. The liner 10 may also be partially orcompletely covered with a coating 20 which dissolves in blood such assugar (FIGS. 13-16). In particular, the distal end 19 of the liner 10may be covered with the coating 20 to form a smooth, atraumatic end asshown in FIG. 13. The coating 20 may extend along the length of theliner 10 as shown in FIG. 14 or may be only at the distal end orintermittent as shown in FIG. 13.

[0075] The liner 10 may also be covered by a removable sheath 21 asshown in FIGS. 17 and 18. The sheath may be removed in any manner suchas tearing along perforations or with a chemical, thermal orelectrolytically severable bond. A filament 23 may also be used to tearthe sheath 21 as shown in FIGS. 17 and 18. The filament 23 may have bothends extending through the catheter rather than having one end extendout of the catheter. The filament 23 is shown separated from the sheath21 for clarity but would either pass inside the sheath 21 or would bepartially embedded in the sheath 21. The sheath 21 can also be a simpleretractable sheath 21 as is known in the art.

[0076] Referring again to FIGS. 10 and 12, the liner 10 is collapsedonto the guidewire 15 so that the liner 10 has an outer diameter ∀ of nomore than 0.065 inch, more preferably no more than 0.040 inch, and mostpreferably no more than 0.026 inch. Stated another way, the thickness ∃of the liner 10 is preferably no more than 0.015 inch, more preferablyno more than 0.012 inch, and most preferably no more than 0.008 inchwhen measured in a radial direction. For a guidewire 15 having a 0.014inch diameter, the liner 10 is preferably collapsed so that the outerdiameter ∀ is 0.020 to 0.032 inch, preferably about 0.026 inch, and thethickness ∃ of the liner 10 is 0.004 to 0.008 inch, preferably about0.006 inch. For a guidewire 15 having a 0.018 inch diameter, the liner10 is preferably collapsed so that the outer diameter ∀ is still about0.020 to 0.032 inch, preferably about 0.026 inch, and the thickness ∃ ofthe liner 10 is 0.003 to 0.006 inch, preferably about 0.004 inch. Theliner 10 also has a high ratio of collapsed cross-sectional area toexpanded circumference in the range of 1:10 to 1:30 and preferably atleast 1:20.

[0077] The relatively small size of the liner 10 advantageously permitsthe liner 10 to be introduced through small and heavily stenosedvessels. The carotid artery is often occluded 95 to 98% and may havediameters as small as 0.020 inch or even 0.010 inch before surgical orinterventional procedures are performed. Conventional stents used in theinternal carotid artery have a collapsed diameter of about 0.065 to0.092 inch and, thus, must often displace the plaque to pass through thevessel. It is believed that some strokes which occur when using stentsin the carotid artery are caused by plaque which is dislodged when thestent is advanced through and expanded within highly stenosed regions.The liner 10 of the present invention protects the vessel as the stentor other device is passed through the vessel. The liner 10 preferablyhas a length (of at least 2 cm and preferably 2-10 cm (FIG. 2). Theliner 10 and anchor 12 have a diameter of 4-10 mm in the expandedcondition with the specific size selected depending upon the size of thevessel being treated. The relative dimensions shown in the drawing havebeen exaggerated to illustrate the features of the invention. In fact,the liner 10 has a length to width ratio ((to ∀) in the collapsedposition of at least 20 to 1, 50 to 1, 80 to 1, and even up to 200 to 1depending upon the particular application. The liner 10 preferablyincreases in outer diameter at least 5, more preferably at least 6 andmost preferably at least 8 times when moving from the collapsed toexpanded positions.

[0078] Referring again to FIGS. 3 and 4, the anchor 12 may be attachedto the proximal end 11 of the liner 10 to expand the end 11 of the liner10, hold the liner 10 in position and reduce flow around the liner 10.The anchor 12 may be any suitable device including a commerciallyavailable nitinol or stainless steel stent such as the MULTILINKmanufactured by ACS and the NIR manufactured by Scimed. The liner 10 isattached to a portion of the anchor 12 with an adhesive, mechanicalinterconnection, thermal bond, suture or the like, or fused or solderedwith radiopaque wire or ribbon. The liner 10 may, of course, be attachedin any other manner. The liner 10 may also be encapsulated betweenlayers of expanded PTFE.

[0079] The anchor 12 and liner 10 may form a continuous, cylindricalshape in the expanded position (FIG. 19) or the anchor 12 may have atapered shape (FIG. 20). The tapered shape of the anchor 12 may beuseful when used in the carotid arteries with the small end positionedin the internal carotid artery and the large end in the common carotid.A method of forming the expanded shape of FIG. 20 is for the anchor 12to have a larger diameter than the liner 10 so that the liner 10 holdsan end of the anchor 12 at a smaller diameter. For example, the anchor12 may be a stent having an 8 mm diameter with the liner 10 having a 6mm expanded diameter so that the liner 10 holds the end 11 of the anchor12 to about 6 mm. Alternatively, the anchor 12 could be designed toexpand to different predetermined diameters at different points alongits length by varying strut lengths along its length.

[0080] The anchor 12 is positioned within an anchor retention catheter22 (FIG. 2). The anchor 12 is naturally biased to the expanded conditionof FIG. 3 and is held in the collapsed position by the retentioncatheter 22. The anchor 12 is deployed by retracting the catheter 22while an inner element 24 holds the anchor 12 at the desired location inthe vessel. The liner 10 is advanced over the guidewire 15 which isadvanced ahead of the catheter 22.

[0081] The anchor 12 may be deployed to extend into the common carotidartery at the bifurcation of the external and internal carotid arteries(FIG. 2) or may be contained entirely within the internal carotid artery(FIG. 21-23). The anchor 12 may also be deployed by inflating a balloon27 as shown in FIG. 21 or may be a shape memory material which is heatactivated. When using a balloon 27 to expand the anchor 12, the anchor12 is preferably a conventional nitinol or stainless steel stentalthough any suitable stent or device may be used. The balloon 27 ispreferably compliant so that a proximal portion of the balloon 27expands to occlude the vessel as shown in FIG. 21 before expansion ofthe anchor 12. Alternatively, the balloon could be non-compliant butdesigned to inflate at a lower pressure than that required to expand thestent. By occluding the vessel, blood flow through the vessel is stoppedso that even if plaque is released the plaque will not flow downstream.Further inflation of the balloon 27 (using inflation source 39) expandsthe anchor 12 into engagement with the vessel wall (FIG. 22). Any of theembodiments of the liner 10 described herein may be used with balloon orself-expanding anchors 12 and stents 26.

[0082] After the anchor 12 has been expanded, the liner 10 can beconfigured to automatically open with blood pressure (FIG. 3).Alternatively, the catheter 22 may be advanced through the liner 10 topartially open the liner 10. The device, such as the stent 26, may alsobe advanced through the liner 10 to open the liner 10. The liner 10protects the vessel to prevent intravascular devices from dislodgingplaque when passing through the vessel. The distal end of the liner 10may also be opened with an elongate element 29, such as a nitinol wire,advanced into the liner 10 to open the liner 10 as shown in FIG. 26A.The element 29 may be advanced and retracted independently with an inneractuator 31.

[0083] Referring to FIGS. 26B and 26C, the elongate element 29A may alsobe advanced into a pocket 35 in liner 10A. The pocket 35 is preferablyformed by simply inverting or everting the end of the liner 10A andattaching the end to another part of the liner 10A to form the pocket35. The elongate element 29A passes through a tube 41, preferably ahypotube, polymer tube or composite tube, which is releasably attachedto the pocket 35. The tube 41 is preferably released by heat,electrolytic detachment, mechanical detachment, dissolution of a bond byblood, or retraction of a retention cord although any suitable methodmay be used.

[0084] The elongate element 29A is preferably made of a superelasticmaterial, such as nitinol, which forms a loop 47 in the expandedposition. The elongate element 29A is contained within the tube 41 whenthe liner 10A is advanced through the vasculature. The liner 10A isadvanced over the guidewire 15 by pushing the tube 41. When the user isready to expand the proximal end of the liner 10A, the element 29A isadvanced into the pocket 35 so that the loop 47 opens the liner 10A asshown in FIGS. 26C and 26D. After opening the proximal end of the liner10A, the liner 10 may be used in any manner described herein. Forexample, the stent 26 may be advanced into the liner 10A to open thenarrowed region of the blood vessel as described in further detail belowand shown in FIGS. 26D and 26E.

[0085] When the device introduced into the liner 10 is the stent 26, thestent 26 is preferably expanded to open the narrowed portion of thevessel as shown in FIG. 25. The stent 26 is mounted to a balloon 33which is coupled to an inflation source 37 (FIG. 1) for inflating theballoon 33. The stent 26 is preferably a conventional nitinol orstainless steel stent. The delivery catheter 22 is preferably introducedinto the liner 10 as shown in FIG. 27 with the distal end of thecatheter 22 positioned beyond the end of the liner 10. The catheter 22is then retracted to expose the distal end of the stent 26. The distalend of the stent 26 is preferably opened first so that plaque is trappedbetween the anchor 12 and stent 26 when expanding the rest of the stent26. The liner 10 may have the openings 25 (FIG. 5) which effectivelyfilter blood trapped behind the liner 10 and help to equalize pressureon opposite sides of the liner as the stent 26 is expanded. The catheter22 may also be used to deliver a distal anchor 43 which holds the distalend of the liner 10 open as shown in FIGS. 29-31. Another stent 45 canthen be delivered to expand the liner 10 between the anchor and distalanchor 43 (FIGS. 32 and 33).

[0086] Referring to FIGS. 34-39, the proximal end of the liner 10 may beexpanded by delivery catheter 50 and then released so that the anchor 12is not required. The catheter 50 has an expanding section 32 which ispreferably inflatable but may also be mechanically actuated. Theexpanding section 32 is coupled to a lumen for inflating the expandingsection 32. The liner 10 is attached to the expanding section 32 withany suitable connection such as glue, suture, or soldered withradiopaque wire or ribbon. The liner 10 is preferably attached to theexpanding section 32 with a thread 34 which passes through the liner 10and expanding section 32. An end of the thread 34 is pulled to releasethe liner 10.

[0087] The expanding section 32 is inflated to expand the proximal endof the liner 10 as shown in FIG. 35. The stent 26 or other device maythen be passed through the liner 10 to open the liner 10 further asshown in FIG. 35. Referring to FIG. 38, the stent 26 is partiallyexpanded so that the liner 10 is held firmly in place by the stent. Theliner 10 is then detached by pulling the thread 34 and the stent 26 isfully expanded. Referring to FIG. 40, the device may also be a filter 36which is advanced through the liner 10 to trap dislodged plaque duringan angioplasty, stent or other procedure. The liner 10 may then beremoved before removing the filter 36 or may be used to line the vesselwhen deploying the stent 26.

[0088] Referring to FIGS. 41-44, the liner 10 may also be everted whenmoving from the collapsed to expanded positions. The liner 10 has theanchor 12 which is self-expanding and held in the collapsed position byretention catheter 37. Pusher element 38 holds the anchor 12 in placewhile retracting the retention catheter 37. A proximal end 40 of theliner 10 is releasably attached to an inner member 42. The liner 10 ispressurized, preferably with saline, using lumen 44 in the pusherelement 38. Once the liner 10 is pressurized, the inner member 42 isadvanced so that the liner 10 everts and moves through the vessel asshown in FIGS. 42-43. An advantage of the everting liner 10 is thatsliding forces between the liner 10 and the vessel wall are reduced whenadvancing the liner 10.

[0089] After the liner 10 has been fully everted, the retention catheter37 is retracted so that the anchor 12 expands and holds the proximal endof the liner 10 open. The liner 10 is then detached from the innermember 42. The liner 10 may have a mechanical connection which isreleased with a push rod or guidewire 43. The liner 10 may also have aseverable bond with the inner member 42 such as a thermally, chemicallyor electrolytically severable bond using the guidewire 43. The device,such as the stent 26, is then delivered through the liner 10.

[0090] Referring now to FIGS. 45 and 46, the liner 10 may also be heldopen slightly at the proximal end 11 by delivery catheter 60. Theproximal end 11 of the liner is preferably held open to a diameter of 6mm to 8 mm or 4 Fr to 7 Fr. One or more filaments 62 hold the liner tothe catheter 60. The liner 10 extends over the distal end of thecatheter 60 but may also be mounted inside the catheter 60. Thefilaments are shown separated from the body of the catheter 60 forclarity but would, of course, either pass through the catheter or beheld close to the catheter 60. The distal end of the stent 26 isinflated first to trap the plaque behind the liner 10 and reduce flowaround the liner 10. The rest of the stent 26 is then expanded in theconventional manner.

[0091] Referring to FIG. 47, another catheter 70 for delivering theliner 10 is shown wherein the same or similar reference numbers refer tothe same or similar structure. The catheter 70 operates similar tocatheter 22 described above in that the liner 10 is mounted to theself-expanding anchor 12. The anchor 12 is held in the collapsedposition of FIG. 47 by an outer wall 72 of the catheter 70. The outerwall 72 is retracted to expose the anchor 12 and permit the anchor 12 toexpand.

[0092] The liner 10 is positioned between a flexible sheath 74 and aninner tube 76. The sheath 74 and inner tube 76 prevent the liner 10 fromcontacting the walls of the vessel and guidewire 15 when the liner 10 isadvanced through the vasculature. The sheath 74 and tube 76 also holdthe liner 10 in the collapsed position although the liner 10 may becollapsed without requiring the sheath 74 and tube 76. The sheath 74 isattached to the outer wall 72 and is retracted together with the outerwall 72.

[0093] A shaft 80 extends through the catheter 62 and a flexible shaftextension 82 extends from the shaft 80. The shaft extension 82 and innertube 76 provide a relatively flexible distal portion to navigatetortuous vessels such as the cerebral vasculature. The flexible shaftextension 82 may be a coil 84 as shown in FIG. 47 or may be a tube 86 ofmaterial as shown in FIG. 48. A distal portion 88 of the catheter 70,which extends from the distal end of the shaft 80, is preferably moreflexible than a proximal portion 90 which terminates at the end of theshaft 80.

[0094] Referring to FIG. 47, the guidewire 15 passes through slots 93,95 in the outer wall 72 and shaft 80 for loading the device on theguidewire 15. Referring to FIG. 48, the guidewire 15 may also passthrough slots 92, 97, 99 in the outer wall 72, inner tube 76 and shaftextension 82. The catheter 70 may, of course, have a continuous lumenwhich extends to the proximal end of the catheter 70. Referring again toFIG. 47, a handle 94 is attached to the outer wall 72 and is pulledrelative to the shaft 80 to retract the sheath 74 and outer wall 72. Theouter wall 72 is preferably made of high density polyethylene having athickness of about 0.005 inch and an outer diameter of 0.040 to 0.070inch, preferably about 0.055 inch. The outer wall 72 preferably has alength of 110 to 150 cm and preferably about 135 cm. The sheath 74 ispreferably made of linear low density polyethylene having a wallthickness of about 0.002 inch and an outer diameter of about 0.049 inch.The inner tube 76 is preferably made of polyimide having a wallthickness of 0.0005 to 0.001 inch and an outer diameter of 0.014 to0.026 inch, more preferably 0.018 to 0.024 inch and most preferablyabout 0.022 inch. The liner 10 is collapsed to have a diameter, length,thickness and length to thickness ratios as described above when mountedto the tube 76. The shaft 80 is preferably a 0.022 inch diameterstainless steel mandrel and the shaft extension 82 is preferably astainless steel coil. The shaft extension is fused to the inner tube 76(FIG. 47). The extension 82 may also be a tube of linear low densitypolyethylene which is extruded and then irradiated with 25/30 Mrads toan outer diameter of about 0.040 and a wall thickness of about 0.018inch (FIG. 48). Any other suitable materials may be used withoutdeparting from the scope of the invention.

[0095] The catheter 70 and liner 10 are used in substantially the samemanner as the catheters and liners 10 described above and the discussionabove is equally applicable here. The liner 10 is advanced over theguidewire 15 to a narrowed region of a blood vessel such as the internalcarotid artery. The liner 10 and catheter have a small profile, asdiscussed above and incorporated here, so that the liner 10 may beadvanced into the narrowed region without dislodging plaque. When theliner 10 is at the desired location, the handle 94 and shaft 80 aremanipulated to retract the sheath 74 and the outer wall 72. When theouter wall 72 and sheath 74 are retracted, the anchor 12 is free toexpand. The liner 10 may then be used in the manner described above. Forexample, the stent 26 or filter 36 may be advanced into the liner 10.

[0096] Referring to FIG. 49, another catheter 100 for delivering theliner 10 is shown. The catheter 100 has the self-expanding anchor 12which is held in the collapsed position by a collar 102. An arm 104 isattached to the collar 102 which in turn is attached to a firstcore-wire 106. The first core wire 106 passes through a shaft 108 whichhas a handle 110 mounted to the proximal end. The handle 110 isretracted to pull the core wire 106, first arm 104 and collar 102 forreleasing the self-expanding anchor 12.

[0097] A tube 112 is fused to the shaft 108 and an inner tube 114 isattached to the tube 114. The arm 104 travels in a slot 116 in the tube114 to stabilize retraction of the collar 102. The tube 112 and innertube 114 form a lumen 118 through which the guidewire 15 passes.

[0098] Referring to FIG. 50, the distal end of the liner 10 is lockedinto a fold 120 at the end of the inner tube 114. A wire loop 122 holdsthe liner 10 in the fold 120. The wire loop 122 is preferably attachedto the collar 102 with a wire 124 embedded in the collar 102. The wireloop 122 is retracted together with the collar 102 so that the distalend of the liner 10 is released as the collar 102 is retracted. The wireloop 122 is preferably a 0.005 inch diameter stainless steel wire. Thefold 120 is preferably made of silicone although other suitablematerials may be used. The shaft 108 is preferably made of stainlesssteel hypotube having a wall thickness of about 0.005 inch and an outerdiameter of about 0.024 inch. The tube 112 is preferably made of linearlow density polyethylene having a wall thickness of about 0.004 inch andan outer diameter of about 0.040 inch. The inner tube 114 is preferablymade of polyimide having a thickness of 0.0005 inch and an outerdiameter of about 0.022 inch. The liner 10 is deployed and used insubstantially the same manner as described above and the discussionabove is applicable here.

[0099] The present invention is also directed to kits 124 which includevarious assemblies as described above. For example, the kit 124 mayinclude the liner 10, delivery catheter 22 and instructions for use 126setting forth any of the methods described herein as shown in FIG. 51.The kits may, of course, also include the stent(s) 26, anchors 12 andstent delivery catheter(s) 22 and/or the filter 36 as well. The kits 124will usually include a container 126, such as a pouch, tray, box, tube,or the like, which contains the devices as well as the instructions foruse 128. The instructions for use 128 may be set forth on a separateinstructional sheet within the package or printed in whole or in part onthe packaging itself. Optionally, other system components useful forperforming the methods of the present invention could be provided withinthe kit 124, including guidewires, introductory sheaths, guidingcatheters, and the like. Any of the devices described herein may form akit with instructions setting forth a method of the present invention.

[0100] While the above is a complete description of the preferredembodiments of the invention, various alternatives, modifications, andequivalents may be used. Therefore, the above description should not betaken as limiting the scope of the invention which is defined by theappended claims. For example, any of the delivery catheters may have aballoon for occluding the vessel while delivering the liner or advancingthe device through the liner and any of the liners may have perforationsto filter blood or may be made of a tightly woven material. Furthermore,the preferred dimensions described herein with respect to any of theembodiments is equally applicable to other embodiments.

What is claimed is:
 1. A method of opening a narrowed region in a bloodvessel, comprising the steps of: providing a liner movable from acollapsed condition to an expanded condition; advancing the liner to anarrowed region of a blood vessel with the liner in the collapsedposition; passing at least a portion of the liner through the narrowedregion of the blood vessel in the collapsed position; positioning astent in the liner so that the stent is also positioned in the narrowedregion of the blood vessel, the liner preventing the stent fromcontacting the narrowed region of the blood vessel; and expanding thestent to open the narrowed region of the vessel.
 2. The method of claim1, wherein: the advancing and passing steps are carried out with theblood vessel being a vessel selected from the group comprising theinternal carotid artery and saphenous vein graft.
 3. The method of claim1, further comprising the step of: expanding the liner before expandingthe stent.
 4. The method of claim 1, wherein: the liner is expanded bythe stent.
 5. The method of claim 1, wherein: the providing step iscarried out with the liner being mounted to a delivery catheter.
 6. Themethod of claim 1, wherein: the providing step is carried out with theliner having an expandable anchor coupled to the liner.
 7. The method ofclaim 6, wherein: the anchor is attached to the proximal end of theliner.
 8. The method of claim 6, further comprising the step of:expanding the anchor with a balloon.
 9. The method of claim 6, furthercomprising the steps of: holding the anchor in a collapsed position; andthe expanding step is carried out by releasing the anchor so that theanchor moves into contact with the vessel wall and toward an expandedcondition.
 10. The method of claim 9, wherein: the anchor is expanded inthe internal carotid artery.
 11. The method of claim 10, wherein: theanchor expanding step is carried out so that the anchor is positioned atthe bifurcation of the internal and external carotid arteries.
 12. Themethod of claim 1, wherein: the providing step is carried out with theliner having a number of folded sections in the collapsed position. 13.The method of claim 12, wherein: the folds are separated by longitudinalcreases.
 14. The method of claim 12, wherein: the providing step iscarried out with the folded sections being wrapped.
 15. The method ofclaim 12, wherein: the providing step is carried out with at least twofolded sections.
 16. The method of claim 12, wherein: the providing stepis carried out with the folded sections being adhered to one another tohold the folded sections in the collapsed position.
 17. The method ofclaim 16, wherein: the providing step is carried out with the foldedsections adhering to one another by application of heat to the foldedsections.
 18. The method of claim 16, wherein: the providing step iscarried out with the folded sections adhering to one another with anadhesive.
 19. The method of claim 16, wherein: the providing step iscarried out with the folded sections being adhered to one another withgelatin, sucrose, glue, low molecular weight polyvinyl alcohol, suture,or fusion or soldered with radiopaque wire or ribbon.
 20. The method ofclaim 1, wherein: the providing step is carried out with the liner beingat least partially covered by a coating in the collapsed position, thecoating dissolving in blood.
 21. The method of claim 1, wherein: theproviding step is carried out with the distal end of the liner beingcovered with a coating which forms a curved, atraumatic surface andcovers a distal end of the folded sections.
 22. The method of claim 1,wherein: the providing step is carried out with the liner being carriedby a delivery catheter, the liner extending from a distal end of thedelivery catheter.
 23. The method of claim 1, wherein: the advancing thestep is carried out by advancing the liner over a guidewire.
 24. Themethod of claim 23, wherein: the providing step is carried out with theliner having a radial thickness of less than 0.020 inch in the collapsedposition, the thickness being measured in a radial direction relative toa hole in which a guidewire is positioned.
 25. A method of protecting abody passage, comprising the steps of: providing a liner movable from acollapsed condition to an expanded condition, the liner everting whenmoving from the collapsed condition to the expanded condition; advancingthe liner to a region of a passageway in a body with the liner in thecollapsed position; passing at least a portion of the liner through theregion of the passageway in the collapsed position, at least a portionof the liner everting when moving from the collapsed position to theexpanded position.; positioning a device in the liner so that the deviceis also positioned in the region of the passageway, the liner preventingthe device from contacting the region of the passageway.
 26. A devicefor protecting a passageway in a body when passing other devices throughthe passageway, comprising: a delivery catheter having a distal end; anda liner coupled to the delivery catheter, the liner being movable from acollapsed position to an expanded position, the liner extending for alength of at least 2 cm and having a diameter of no more than 0.060 inchalong the length when in the collapsed position.
 27. The system of claim26, wherein: the liner is releasably coupled to the delivery catheterand extending distally from the distal end of the delivery catheter. 28.The system of claim 26, wherein: the liner forms a throughhole whichreceives a guidewire when advancing the liner through a narrowed vessel.29. The system of claim 26, wherein: the liner has an expandable anchorfor moving an end of the liner toward the expanded position.
 30. Thesystem of claim 26, wherein: the anchor is mounted to an inflatableballoon which expands the anchor.
 31. The system of claim 26, wherein:the balloon has a proximal portion which extends beyond the anchor, theproximal portion expanding more than the anchor initially so that theproximal portion occludes the vessel before full expansion of theanchor.
 32. The system of claim 26, wherein: the liner forms a number offolded sections in the collapsed position.
 33. The system of claim 32,wherein: the liner has at least two folded sections.
 34. The system ofclaim 32, wherein: the folded sections are wrapped around one another.35. The system of claim 26, wherein: the liner has a diameter of no morethan 0.060 inch along the length in the collapsed position.
 36. Thesystem of claim 26, wherein: the liner expands to a diameter of at least4 mm in the expanded condition.
 37. The system of claim 26, wherein: atleast the distal end of the liner is covered by a coating, the coatingcovering the distal end of the folded sections.
 38. The system of claim26, wherein: the liner is a tube of material when in the expandedcondition.
 39. The system of claim 26, wherein: the delivery catheterhas an expandable section, the expandable section being movable from acollapsed condition to an expanded condition; and a proximal end of theliner being coupled to the expandable section so that the proximal endof the liner is expanded when the expandable section is expanded. 40.The system of claim 39, wherein: the expandable section is coupled to aninflation lumen and is inflated when moving to the expanded condition.41. The system of claim 40, wherein: the liner is releasably attached tothe expandable section.
 42. A method of advancing a device through apassageway in a body, comprising the steps of: providing a liner movablefrom a collapsed condition to an expanded condition; advancing the linerto region in a passageway in a body with the liner in the collapsedposition; passing at least a portion of the liner into the region in thecollapsed position; and introducing a device into the liner so that thedevice is also positioned in the region of the passageway, the linerpreventing the device from contacting the region of the passageway. 43.The method of claim 42, wherein: the introducing step is carried outwith the device is selected from the group consisting of a stent,filter, angioplasty balloon, drug delivery device or catheter, lasercatheter, and ultrasound catheter.
 44. The method of claim 42, furthercomprising the step of: expanding the stent to trap the liner betweenthe stent and the vessel wall.
 45. The method of claim 42, wherein: theproviding step is carried out with the liner having an outer diameter ofno more than 0.065 inch in the collapsed position.
 46. The method ofclaim 45, wherein: the providing step is carried out with the linerhaving an outer diameter of no more than 0.040 inch in the collapsedposition.
 47. The method of claim 42, wherein: the providing step iscarried out with the liner being collapsed to a radial thickness of nomore than 0.025 inch.
 48. The method of claim 42, wherein: the providingstep is carried out with the liner being collapsed to a radial thicknessof no more than 0.020 inch.
 49. The method of claim 42, wherein: theproviding step is carried out with the liner being mounted onto a tubeof material having a lumen; and the advancing step is carried out withthe liner being advanced over a guidewire passing through the lumen inthe tube.
 50. The method of claim 42, wherein: the providing step iscarried out with the liner having a length to width ratio of at least 20to
 1. 51. The method of claim 42, wherein: the providing step is carriedout with the liner having a length to width ratio of at least 40 to 1.52. The method of claim 42, wherein: the providing step is carried outwith the liner having a length to width ratio of at least 60 to
 1. 53. Adevice for protecting a passageway in a body when passing other devicesthrough the passageway, comprising: a liner movable from a collapsedposition to an expanded position, the liner having a diameter of no morethan 0.018 inch in the collapsed position, the liner having an outerdiameter of no more than 0.040 inch when in the collapsed position; andan expandable anchor attached to the liner, the anchor being movablefrom an expanded shape to a collapsed shape, the anchor being configuredto hold the liner at a position in a passageway in a body.
 54. Thedevice of claim 53, wherein: the liner has an outer diameter of no morethan 0.026 inch.
 55. The device of claim 53, wherein: the liner has alength, the length to diameter ratio for the liner being at least 20to
 1. 56. The device of claim 55, wherein: the length to diameter ratiois at least 50 to
 1. 57. The device of claim 55, wherein: the length todiameter ratio is at least 80 to
 1. 58. The device of claim 55, wherein:the anchor is mounted inside a delivery catheter which holds the anchorin the collapsed position, the anchor being naturally biased toward theexpanded position.
 59. The device of claim 53, further comprising: aretractable sheath disposed over the liner when the liner is in thecollapsed position.
 60. The device of claim 53, further comprising: aninner tube which has a throughhole to receive a guidewire, the linerbeing mounted over the inner tube so that the inner tube prevents theliner from contacting the guidewire.
 61. The device of claim 53,wherein: the liner has a thickness in a radial direction of no more than0.012 inch.
 62. The device of claim 53, wherein: the liner has a firstend and a second end, the anchor being attached to the first end and theliner being free at the second end when in the expanded position. 63.The device of claim 53, wherein: the liner forms folds in the collapsedposition.
 64. The device of claim 53, wherein: the liner has a flexible,non-metallic tube.
 65. The device of claim 64, wherein: the liner has anexpandable metallic anchor which is configured to open an end of theflexible tube.
 66. The device of claim 53, wherein: the liner has acollapsed diameter of 0.020 inch to 0.032 inch.
 67. A method ofprotecting a body passageway when advancing a device through the bodypassageway, comprising the steps of: providing a liner movable from acollapsed condition to an expanded condition, the liner having an anchorat an end of the liner to anchor the end of the liner in the passageway;advancing the liner to a region of a passageway in a body with the linerin the collapsed position; expanding the anchor with an expandabledevice, the expandable device and the anchor blocking fluid flow throughthe passageway; passing at least a portion of the liner through theregion of the passageway in the collapsed position; positioning a devicein the liner so that the device is also positioned in the region of thepassageway, the liner preventing the device from contacting the regionof the passageway.